Set notation: Difference between revisions

Revision as of 03:32, 27 September 2017

Revision as of 03:33, 27 September 2017

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== Focusing on the membership of a set ==

In many contextcontexts one is interested more in the elements that constitute the set than in the single entity comprising those elements, for instance where stating an [[extensional definition]] of the set. Here the elements, whether expressed discretely or in some aggregate manner, are enclosed in braces.

The simplest notational approach of this type, which is feasible only for fairly small sets, is to enumerate the elements exhaustively. Thus the set of suits in a standard deck of playing cards is denoted by {♠,&nbsp;<span style="color:red">♦</span>,&nbsp;<span style="color:red">♥</span>,&nbsp;♣} and the set of even [[prime numbers]] is denoted by {{math|&#123;2&#125;}}. This approach also provides the notation {{math|&#123;&#125;}} for the empty set.